Reflector for search-lights.



PATENTED JUNBSO, l908.--

J. A. REY. REFLECTOR FOR SEARCH LIGHTS.

APPLICATION FILED DEC. 15. 1.996.

@rumntoz Sire-nay 55 It is known thatthe atmosphere principally gprovement in Reflectors for Search-Lights,

- the maximum useful effect, that. is to say, for

.maxim'um visibility of the objects 1lumi-- purely geometrical condition, the spherical fact richest in blue and violet rays, that is to .TEAN ALEXANDRE REY, OF PARIS, FRANCE.

REFLIILG'JJOR FOR Specification of Letters Patent.

SEARCH-LIGHTS.

7 Patented June so, 1908.

Application filed December 15, 1906. Serial No. 29 1,951.-

To all whom it may concern:

Be it known that I, JEAN ,ALEXANDRE REY, of 26 Avenue de Sufi'ren, Paris,-France, engineer, have invented a new and useful Imwhich improvement is fully set forth in the following specification.

This invention has for itsobject a mirror formed of gilded metal for reflecting the light of an electric arc to a distance which secures a given. expenditure ofelectric energ the nated. For this purpose the first condition to be fulfilled is to obtain a concentrated beam, any dispersion of the luminous rays being avoided. At the presenttime there are numerous lanterns which satisfy this aberration of the reflecting surfaces being ,small enough for the concentration at a distance to be sufficient for practical purposes. In addition to this condition, the present in.- vention fulfils two other very important conditions which greatly increase visibility. The first consists in giving to the beam a color approaching that of solar light. The human eye is best suited for seeing objects in daylight and to make objects visible to it, it is best that they should be illuminated with a light havin a general tint approaching that of the so ar rays. This condition has not hitherto been attained in electric arc lanterns. The light of the electric arc is in say, in rays whose ray lengths are least, and such li ht is therefore far removed in its iproperties from day-light, alnd is far from ulfilling the above condition. It has before been proposed in public are lighting that the carbons should contain mineral substances which give to the light a yellow color in place of a violet color. The use of such carbons in a lantern allows a colored-ray to be obtained, having a tint approaching more nearly to daylight. This solution of the problem leads however to various difliculties and this inven tion attains the same result by different means. The second condition to be fulfilled consists in em loying a light whose rays are only slightly a sorbed bythe atmosphere or at most, to a less' degree than are luminous rays of the ordinary are. Light rich in yellow and orange rays fulfils this condition.

this is that all long distance lights, such as lighthouse or search lights become reddish at a sufficient distance from the source of light. Hitherto, in electric lanterns, onlysilvered glass mirrors havebeen, em loyed, the silver eing de osited by chemica means upon the glass. The rincipal reason for this is first the 'ease'wit which this metal is de osit'ed upon the glass and second its great re ecting power which is. reater than that of any other metal. The re ecting power of silver-is however practically the same for all the wave length of the spectrum, and it follows that silver does not itself color the beam which it reflects thus the electric are light reflected b lantern having asilvered lass mirror, is. bliieish, that is to say,is ric in blue and violet rays, for these are exactly the Jays which are most prominent in the ordinary electric arc. I

This invention overcomes these defects and complies with all the conditions enumerated above by the use 'of' a mirror covered with a reflecting metal which is old instead of silver. Gilded reflectors have een known from the earliest times but they have never been employedin electric lanterns.

Experience has shown that agilded mirror in reflecting the beam of the electric arc, gives it a much warmer yellowish tint than a silvered reflector; objects illuminated by such beam have much more nearly the apabsorbs the more refrangible rays, that is'to and their visibility is considerably increased owing to this. i Moreover, a beam coming o from amirror of this nature loses a smaller proportion of its intensity in passing through an atmospheric layer of a given thickness than a beam derived from a silvered mirror. The reflecting power of gold for the wave lengths corresponding to the less refrangible portion of the spectrum, that is to say, from' red to yellow is besides practically the same as that of silver. The reflecting power of gold is also considerably less than that of silver for rays from yellow to violet, but these are precisely the rays which the atmosphere absorbs most easily. Itmay be said therefore that the total light reflected by a gilded mirror will be less than the light reflected by a silver-ed mirror, but that a greater proportion of this light will reach the object and consequently that the total useful effect will remain as high.

The coloration of the objects being more satisfactory to the eye, it is not to be wondcred at that the visibility, which is the ultimate result it is desired to obtain, should be increased. I In the accompanying drawing I have shown for purposes of i lustration a search light in a casing A, with the usual electrodes B and U, and em iloying a reflector D having. its surface E gilt ed in accordance with this invention. i

The gilded metal mirror forming the subject of this invention may be manufactured by anyof the processes hithertoemployed for the manufacture of metal reflectors; it

may be formed of metal plated with gold, or metal gilded b electrolysis, and then suitably burnished an polished. The Cowper Coles process ma be employed to construct the reflector. his process consists in chem? ically depositing upon a suitably shaped and polished parabolic glass mold, a thin layer of silver which is then covered with an electrolytic deposit of copper, thus forming the body of the reflector.

from the glass mold on which it is formed, a

reflector is obtained whose curvature is rigorously exact and which has fine reflecting power. The silvered mirror obtained is then covered by electrolysis with a layer of ld which is then suitably polished, the si ver only serving to support the gold. This process makes it possible to manufacture arellector having the exactitude desired, the

and thatlthe said Letters [snap] tjarrection in Letters PateritNo. 892

On separating the reflector,

It is hereby certified that in Letters Patent No. 892,087,

the application of Jean Alexandre Rey, of Paris,

reflecting metal of which is gold and hot sil ver and which fulfils all the conditions indicated above. The gold may moreover be re.- placed by an other metal having similar properties. he method of manufacturing these reflectors is not limited to a parabolic form, but it is equally applicable to any concave metallic surface formed to a h perb olic or elliptic curve b Y any mechanical process, the metallic mass eing covered with a layer of gold and suitably polished. The mirror aboye described has moreover the advan tage of preventing all )ossible' alteration to the reflecting surface, ,t e gold not being attacked by the electric arc.

Having now particularly described and ascertained the'nature of my said invention and in what manner the same is to be per formed, I declare that what. I claim is:

4 1. The combination with an electric arc lamp, of a reflector having its reflectingsurface of gold. i

.2. The combination with an electric arc lamp, of a paraboliform reflector having its reflecting surface of gold.

3. A search-light comprising an electric arc and reflecting means to protect the light in substantially parallel rays, saidv means having its reflecting surface of polished gold. In testimony whereof I have signed this specification in the presence of two subscribing witnesses.

JEAN ALEXANDRE REY.

, Witnesses:

granted June 30, 1908, upon France, for an improvement in Reflectorsfor SearchLights, an error appears in the printed specification requiring correction, as follows: In line 64, page 2, the word protect should read project; Patent should be read with this correction therein that the same may conforni to the record of the case in the Patent Office.

Signedand sealed this 21st day of July, A. D., 1908. I i V E. B. MOORE,

Commissioner of Paten s.

tion of this light will reach the object and consequently that the total useful effect will remain as high.

The coloration of the objects being more satisfactory to the eye, it is not to be wondcred at that the visibility, which is the ultimate result it is desired to obtain, should be increased. I In the accompanying drawing I have shown for purposes of i lustration a search light in a casing A, with the usual electrodes B and U, and em iloying a reflector D having. its surface E gilt ed in accordance with this invention. i

The gilded metal mirror forming the subject of this invention may be manufactured by anyof the processes hithertoemployed for the manufacture of metal reflectors; it

may be formed of metal plated with gold, or metal gilded b electrolysis, and then suitably burnished an polished. The Cowper Coles process ma be employed to construct the reflector. his process consists in chem? ically depositing upon a suitably shaped and polished parabolic glass mold, a thin layer of silver which is then covered with an electrolytic deposit of copper, thus forming the body of the reflector.

from the glass mold on which it is formed, a

reflector is obtained whose curvature is rigorously exact and which has fine reflecting power. The silvered mirror obtained is then covered by electrolysis with a layer of ld which is then suitably polished, the si ver only serving to support the gold. This process makes it possible to manufacture arellector having the exactitude desired, the

and thatlthe said Letters [snap] tjarrection in Letters PateritNo. 892

On separating the reflector,

It is hereby certified that in Letters Patent No. 892,087,

the application of Jean Alexandre Rey, of Paris,

reflecting metal of which is gold and hot sil ver and which fulfils all the conditions indicated above. The gold may moreover be re.- placed by an other metal having similar properties. he method of manufacturing these reflectors is not limited to a parabolic form, but it is equally applicable to any concave metallic surface formed to a h perb olic or elliptic curve b Y any mechanical process, the metallic mass eing covered with a layer of gold and suitably polished. The mirror aboye described has moreover the advan tage of preventing all )ossible' alteration to the reflecting surface, ,t e gold not being attacked by the electric arc.

Having now particularly described and ascertained the'nature of my said invention and in what manner the same is to be per formed, I declare that what. I claim is:

4 1. The combination with an electric arc lamp, of a reflector having its reflectingsurface of gold. i

.2. The combination with an electric arc lamp, of a paraboliform reflector having its reflecting surface of gold.

3. A search-light comprising an electric arc and reflecting means to protect the light in substantially parallel rays, saidv means having its reflecting surface of polished gold. In testimony whereof I have signed this specification in the presence of two subscribing witnesses.

JEAN ALEXANDRE REY.

, Witnesses:

granted June 30, 1908, upon France, for an improvement in Reflectorsfor SearchLights, an error appears in the printed specification requiring correction, as follows: In line 64, page 2, the word protect should read project; Patent should be read with this correction therein that the same may conforni to the record of the case in the Patent Office.

Signedand sealed this 21st day of July, A. D., 1908. I i V E. B. MOORE,

Commissioner of Paten s.

t i t I I It is hereby certified that in Letters Patent No. 892,087, granted June 30, 1908, upon the application of Jean Alexandre Key, of Paris, France, for an improvement in Reflectors for Search-Lights, an error appears in the printed specification requiring correction, as follows: In line 64-, page 2, the word protect should read project; and thattthe said Letters Patent should be read with this correction therein that l the same may conform to the record of the ease in the Patent ()fiice.

Signed and sealed this 21st day of July, A. I) 1905.

[SEAL] E. B. MOORE,

Commissioner of Patents. 

